Protractor



M. A. SHARAR Jan. 1, 1935.

PROTRACTQR Filed June 22. 1952 2 Sheets-Sheet l Lj az War/i271? /mrkr INVENTQR ATTO R N EY Jan. 1, 1935. M. A. 'SHARAR 1,986,684

PROTRACTOR Filed June 22, 1952 2- Sheets-Sheet 2 3 I I?" k 3/ INVENTOR ,ATTORN EY J and unbrokenly, 10min. other words,

v fro the attainment of 7 wention eonsists in the imprevement lie 'einafter :described and definitely claimedw 1 In the drawings:

i a: i 1 5 9 4 i w 9f he P3 34:

5 inventibn has referenQe tesbevel iiiotf torsls esiened orlali cla e o Qr h r I g-l es areto beqlaid out -er measured.

sbisss F r the in ent on i o mov es inf stnumentby means ofwhich variousyanglesgand idepths may be determined, the instrument \be- 'in amblenf adjustment-for aL-Wide variety of uuees and in :reaiity the instr ment. comprises, in nQmbination, a square, as well as a; bevel prqtrac;

tor; ,zand is ;posit v 1;y,capab1e sf; nei qm nelall 1111 the n e sd fu qt n nm ihe hyismh; ustruments s Another object is the provision 9i, a pret raeton hichm belaid,a ti ponirald w nsis k tehro iohiectandwadiusted :with'respect to langle orl vdegree, land whereby fl-the ,lin thus 3Q t ained may pew-scribed alqng theiinstrlnnent w er by s1 e f a combined. bevelwp iotraetq rgr vvhigli is hers i b im l y i l 9 hc% inaccurat ad ustment and reliability an d ency in practical use; 1

the io reg eing the finfi a 1 Figure 2 is an edge view theregn.

Figure 3 is a' sectional view aproxin ateljn w the line 3 3 of Figure 1.

Figure -4 is a tiqansyerse ,seotibnaliyievs fie line of Fi une 1.; l

N m re 5 is a lan wielw' bi thew instrument s head which may be jal 1 metre 6 is a plan view the edge plat i r a mpld d-J i g F gul e '1 is .ajsidejeleya onthereo I Figure 8 is a plan iew of tl einstrument shewg the same ,folded to bring thefbl ades' thereof a in ts ch t et; i f Figure9-is a pla-nxview showing the instrument pfovidedwith the attachment disclosed by Figure 5 -and withthe head byFigflresfi'andiQ w Figure 10 is a detail perspective viewof the islidable latch. i

I'Ihe head pf my improvementi icbmpiises an inner .disc 1 (andan ,outer andfismailer dis'c 2.

The 'sma'ller .disc 2 is arranged on athe center of the outerface of the inner disc fliesediscs ,erd sd oifsetior irreguiaresuriaces are gpresented py a he i st ument to interfere with he. s ribin qpr hlri i a A- urt and important ab e he m vie i s m men ese er bly nwthe-nature t asses.-'eentrally throu hmoth an .zih ee ed i npibeing: pmvidedrwith za slot :for

ia'fifiplitl pfln flw f5hfil'fi4 that is com.- in t, he'eiitr byiaipenpherallw l l kqti Miia is screwed omthe bblt amin e hits; :shankthatmwss th ,u hiii ie'zdiss' s meierablmsquareland pro;- ri' -il dz sit s then weansirtomhoidingthseoit f-mm ii ineeed li viieadmmhe fboltj siembedded in h qsssm nded the eier t Qm th s: surfac .ii @hB.;1Pl 1'PO5fi wi1hi5idnventionwrinfilude glWtdQElflS; theisaid=er=aduetions app aringupon e ne malimi we .aces-pf'itiiemeaidiidiscmrimore l ealsin ,iennesitemhe ieldge frithe ixom, 1 .1 is pxoiectedianerm t {Ii'herecmnfl lia rwnat will .rtermibs enter edge istmi ht whic st aight ed e:terminates=.sm a linefiwfitli m phe yx t sthe disc W in i- The disc z also zhas its water ermermally visible wl eyfi edfmm:itsbedyADits outerlperimeter 'fi d'lpmltifln marries tamero mark i8 ineluded infa smile-ll; the? zemrmank meing adapted to register with the graduations 6, while the s fi dllatiqnssofhthesscale: Suienabl'emne teildet'erf ractionalmaets byliminutestiofwtliersub fa-said rscale'vhavi-ngvthez graduations i6.

extensiqni J10,-aone;o'f awhose iedges isin Ia elane mithzthei axial-:Cente 'q-pfqiihevdise aznd the i aid armlbeing pfwthersamewwidltn as'vthe arm'W,

{has its oppusitei (ed e: m i ectingwh n n rripl'ifi iofithe disc 1.; i'Ilhe inner: endof tliisarm, .11' ,whie'h the disc'liissprovitied; shes-sits rear me Qut'awa/yz nrmutehed tomnovi'de both=la beveled :axndzflatisurfaace that :rides on the beveled and on the straight outer and normallyi wmsiblelface of thel-diseiL'zarid the:.tiuter ancl=:fialt' face bf the enn The arm-'iifromi s 'outers traighhand active edge, rslotted l'bngitudinallyb andthe arm 10 i from and.='ontward 0f the portion ther'eef ina e filliw eli nfii l-Ethe said disc: ziimmwits outer heaish'owing of- {the drawings slots are similar; Ct :liave nbt 'x'ie ed it necessary to illustrate the slot in the-Wei 10'; bilfiiiave the inner straight wall of the slot or opening By providing the arms with this particular. form through the said slots or openings vto engage with'the walls thereof the.bladeza-loithat passes through the slot or opening..1 1. in @the .arm 10, and the blade 17 that passes through the lo'n'gi tudinal slot or opening in the arm ,7. Both offthe blades are of a similar construction and are of substantially" the 5 same "length and" each of the blades has its outer straight edge formed with a depending rib 18 whose inner shoulder conta'cts"with the' louterffac'e offthe' rib 13 and the inner 'reduced an'd flat face" of' the said blade rests onthe 'inner race of the X33813. The under face of the reduced poltiolis 6f the blades 16 and The "grooves 19 receive tlierein tongues 2Q that pro? .ject from: thelower and reduced ends 21 of blocks 22.. Each of theiblbeks'is received-"in'theslots 11 and 12:at' 'the rear of; the bladesilo and 1'7 and are 'alsoreceivedin substantially rectangular recesses 2 3' -in the said -arms "7' an'd 1Q. The blocks have central threaded openings'jther'ein -forfthe reception of-"jthe" threaded ends of "shanks 24 that'ipass tliroughpfzening's on the inner side of therarm 7iandthe "outei endjof'the arm 10. The 'shanks' 14 have out'er'knurle'd 'heads' 25, respec- .tively,5 and by manipuIat'ing-theheads the threade'd shanks will muse the' clamping blocks 22 to move into the pockets provided-therefor so that their:lipsfzfiiwill draw upon the iii'iier shoulders afforded-by the grooves "IQ -inthe said blades'for "tightly: clamping the I blade f in the arm I and for arranging the outer face of 'the 'blade'l'l flush with the outer edge of thearni rand for likewise positively holding the blade 16 at -a right angle 'witharespect to the 'arm 10. Obviously by'slightlly'tunscrewingthe bolts the 'blad'eslo' and 17 may be?movediilongitudinally through "the arms '7 rand-10;; ,2.)

;With a construction as above described is to be notedthatthe 'inn'enfaces of the arms of the head "or disc, 15- are; straight and are flush with .eachotlier; s'o'tha't'the instrument may rest upon a rflat surfaceoff-either"anobject or a drawing *shetxand by emerely' regulating thefnut 5 either of:.the bladecarryingiarms may be adjusted to any' desired angle Eof inclination with "respect -to .the-othernarm' and thenthe end of'one arm -is rbrought into contact with the edge of the other jarmso thatqa continuous surface is provided by ,theinstrdment for r scribing .an angle :upon the biectoripaperfiix."-11: p V

' It will;- be; further notedcthat after ithe'arms and the] bladesuare: adjusted; and'the nut i5 is screwed home on the bolt 3 the arms'and blades will be retainedin: such adjusted relation so that the instrument canbeftakenzfrom; place ,to .place and the anglelines may be scribed upon other objects or the instrument may be placed iupon a finished object to positively ascertain that'the angle of thefzsidesyor walls, thereon are as deter- As disclosed by Figure 8 of the drawings the blade 17 may be moved through the arm 7 a .In instances where it is desired that one of the of slots or openings there may be easilypassed blades be retained ofiset or at an angle with reclosed by Figure- 5 of the drawings is employed. This attachment comprises a metal member having a central; approximately half-circular portion 2-7zfron1 whose ends there are projected oppositely directed arms 28 and 29 the arm 28 being of a less length than the arm 29. These arms are provided-with slots or groovesfof a construction similar to those previously described sothat blades; similar to the; blades 16 and 17 may be interfitted' With the ar'ms*28 and 29 respectively. In theshowing of Figure 9"the arm 28 isreceived through the slot or opening 11 inthe arm 10 of the instrument and o'lampedtherein. The *inri'erwall provided by the arched portion 27 peripherally engages 'with the disc 1-.- A deterniined angle 'maybe'h'ad' by turning the arm 10 on the head 1, and the shoulder 30, at the juncture of the saidrounded portion-27 of the arm 'zoeo tactifi with the arm 7 will limit the angularadjustment of th'efarm 29; A blade is inserted for head 31. The edge plate'or head hasa central substantially; L-shaioed slot 32- therethrough I to receive therein the shouldered portion of the blade 16 or 17. Partly projecting into this'slot '32' there'is'the lip 20 of a latching block similar to the latching block 22 and this lip is designed to be, "reoeivedin thegroove 19 of theblade. The block" is operated by anadjusting screw whosemilled head 33 is arranged along one of the ends offthesaid edge plate or head The 'ed'geplate or head, ,whenproperly adjusted on the blade, holds the blade square at the edge of any object. A blade may, of course, be at- 'tachedto the arm' 28 and the head or edge plate may be transferredfrom the blade on the arm 29 onto the last named blade, thus making it possible to scribe a right or a left angle with one setting ofthedial.

It is to be noted that the'im'provement is simple and compact. With the device, tapered or round objects which-'are' very small in diameter can be measured because both blades can be brought face toface and said'blades cannot pass over each other. i The protractor may bealso employed for measuringflongnarrow. tapers as the blades may be swungnwith respect to each other approximately a radius of 13i5degreesf Because of its flat back surface the same can be arranged on and snuglyengagewith an object to be scribed .or measured. The devicemay be'employed as a rule, as a dividing implement as well as, for marking equidistantly spaced points through the medium of the pointed ends of the blade and can- ;vention are capable of extended application and flush with the rear face of the larger disc and I do not wish to be restricted to the precise details herein shown and described.

f a As disclosed by Figure 3 the disc2 of the pro tractor has its inner flat-face provided with an annular boss 50 which is received in an annular groove in the outer face of the disc 1 so that the said disc 2 is at all times retained from movement on the disc 1. v

Having described the invention, I claim:

A protractor comprising two concentrically relatively rotatable discs having, a common axis concentric thereto, one of said discs being larger than the other and being provided with a degree scale, the smaller disc having a line to register with the degree scale and likewise being provided with a minute scale, said larger disc carrying an arm whose outer edge is in a linewith the margin of the disc, the smaller disc alsocarrying an arm whose outer portion is thickened on one of its faces to permitof the said face being arranged the arm carried thereby, both of said arms having longitudinal openings afiording inner shoulv 1 ders, the opening in the arm of the larger disc being extended through the outer end thereof and that in the arm of the smaller disc being arranged transversely therethrough, a member having op positely extending arms and an arched portion connecting the arms, one of said arms being received through the transverse groove in the smaller disc carrying arm, means for removably securing the same in said arm, and the arms of the said member being slotted for the reception of blades, a blade removably secured in the arm of the larger disc member, means removably securing the blade therein, a slidably arranged head transversely on said blade and means for removably sustaining the head on the blade.

MARTIN A. SHARARN 20 

